Which one of the following is metabolic waste of protein metabolism

Options

A. Urea, ammonia and `CO_(2)`
B. Urea, ammonia and creatinine
C. Urea, ammonia and alanine
D. Urea, nitrogen and `O_(2)`

Explanation

To determine which of the following is a metabolic waste of protein metabolism, we need to analyze the options provided:

1. **Understanding Protein Metabolism**: When proteins are metabolized in the body, they break down into amino acids. The amino acids can be further deaminated, which means that the amino group is removed. This process produces several waste products, primarily urea, ammonia, and creatinine.

2. **Analyzing the Options**:
- **Option A**: Urea, ammonia, and carbon dioxide.
- Urea and ammonia are indeed products of protein metabolism, but carbon dioxide is primarily a product of carbohydrate and fat metabolism, not protein metabolism. Therefore, this option is incorrect.

- **Option B**: Urea, ammonia, and creatinine.
- All three substances listed here are metabolic wastes associated with protein metabolism. Urea is formed from the breakdown of amino acids, ammonia is a direct product of deamination, and creatinine is a waste product from muscle metabolism that also relates to protein metabolism. This option is correct.

- **Option C**: Urea, ammonia, and alanine.
- While urea and ammonia are metabolic wastes, alanine is an amino acid and not a waste product. Hence, this option is incorrect.

- **Option D**: Urea, nitrogen, and oxygen.
- Urea is a waste product, but nitrogen and oxygen are not specific metabolic wastes of protein metabolism. Nitrogen is a component of amino acids, and oxygen is involved in cellular respiration. Therefore, this option is also incorrect.

3. **Conclusion**: Based on the analysis, the correct answer is **Option B: Urea, ammonia, and creatinine**.